Optimal preventive strike strategy vs. optimal attack strategy in a defense-attack game

This paper analyzes an attack-defense game between one defender and one attacker. Among, the defender moves first and allocates its resources to three different methods: employing a preventive strike, founding false targets, and protecting its genuine object. The preventive strike may expose the genuine object, and different from previous literature, a false target may also be detected to be false. The attacker, observing the actions taken by the defender and allocating its resources to three methods: protecting its own base from the preventive strike, founding false bases, and attacking the defender's genuine object. Similarly, a false base may be correctly identified. Different from previous methods in evaluating the potential outcome, for each of the defender's given strategies, the attacker tries to maximize its cumulative prospect value considering different possible outcomes. Similarly, the defender maximizes its cumulative prospect value, assuming that the attacker chooses the strategy to maximize the attacker's cumulative prospect value. Numerical examples are presented to illustrate the optimal number of bases to attack by preventive strike, and the optimal number of targets to attack by attacker

Risk-attitude-based defense strategy considering proactive strike, preventive strike and imperfect false targets

This paper analyzes the optimal strategies for the attacker and the defender in an attack–defense game, considering the risk attitudes of both parties. The defender moves first, allocating its limited resources to three different measures: launching a proactive strike or preventive strike, building false targets, and protecting its genuine object. It is assumed that (a) launching a proactive strike has limited effectiveness on its rival and does not expose the genuine object itself, (b) a false target might be correctly identified as false, and (c) launching a preventive strike consumes less resources than a proactive strike and might expose the genuine object. The attacker moves after observing the defender's movements, allocating its limited resources to three measures: protecting its own base from a proactive strike or preventive strike, building false bases, and attacking the defender's genuine object. For each of the defender's given strategies, the attacker chooses the attack strategy that maximizes its cumulative prospect value, which accounts for the players’ risk attitudes. Similarly, the defender maximizes its cumulative prospect value by anticipating that the attacker will always choose the strategy combination that maximizes its own cumulative prospect value. Backward induction is used to obtain the optimal defense, attack strategies, and their corresponding cumulative prospect values. Our results show that the introduction of risk attitudes leads the game to a lose-lose situation under some circumstances and benefits one party in other cases

Autonomous Weapon Systems, International Crises, and Anticipatory Self-Defense

Autonomous Weapon Systems (“AWS”) present novel challenges for the laws of war. But the voluminous literature on the use of AWS during war – i.e., under the jus in bello framework – almost entirely ignores the challenges that AWS pose for jus ad bellum. This Note is among the first legal works to systematically analyze the question of when AWS may transition from peace to violence; that is, from crisis to war. Specifically, it asks when an autonomous weapon system may lawfully use force in anticipatory self-defense. This Note argues that with the right rules, AWS may reduce the risk of jus ad bellum violations and dampen escalation, improving compliance with international law and potentially saving lives

Optimal defence-attack strategies between one defender and two attackers

This paper analyses the optimal strategies for one defender and two attackers in a defence-attack game, where a) the defender allocates its resource into defending against and attacking the two attackers, and b) the two attackers, after observing the action of the defender, allocate their resources into attacking and defending against the defender, on either a cooperative or non-cooperative basis. On a cooperative basis, for each of the defender’s given strategies, the two attackers work together to maximise the sum of their cumulative prospect values while anticipating the eight possible game outcomes. On a non-cooperative basis, for each of the defender’s given strategies, each attacker simultaneously yet independently tries to maximise their own cumulative prospect value. In both cases, the defender maximises its cumulative prospect value while anticipating the attackers’ actions. Backward induction is employed to obtain the optimal defence and attack strategies for all scenarios. Numerical examples are performed to illustrate the applications of the strategies. In general, we find two opposing effects considering the attackers’ strategies and analyse the alteration of strategies for the participants under two different risk preferences: risk-averse and risk seeking. The reasons for the alteration are also performed to illustrate the practical applications

Institutional Choice and Targeted Killing: A Comparative Perspective

For over a decade, the use of targeted killing has been one of the most controversial issues in counterterrorism policy and law. One longstanding debate over this tactic concerns the allocation of decision-making and oversight authority among the branches of government. As attempts to settle this debate through textual and historical sources yield indeterminant answers, scholars tend to examine them through a functionalist prism, asking what institutional structures best serve the interests of national security while ensuring adequate accountability and preventing unnecessary force. This article, retaining that functionalist framing of that issue, will approach the question through a comparative law analysis. Three of the countries most heavily engaged in global counterterrorism—the U.S., the U.K., and Israel—have adopted substantially different approaches for regulating counterterrorism targeting, each according a primary supervisory role to a different governmental actor: the Executive in the U.S., Parliament in the U.K., and the Judiciary in Israel. This article describes, compares, and critically analyzes these approaches. Drawing on comparative institutional analysis theory, it then examines the findings and reaches three main conclusions. First, that in light of the judiciary’s unique structural perspective and expertise, some judicial involvement in developing the legal standard that guides and constrains government action is desirable. Second, that suboptimal decision-making and illegality due to executive bias are more likely to occur where the executive is accountable only to its own internal oversight mechanisms. And third, that in both presidential and parliamentarian systems, legislators do not have and are unlikely to have any sort of meaningful influence on executive behavior in this domain. The article concludes by suggesting a few possible institutional reforms

The use of armed drones by the United States against Al-Qaeda and its ‘associates’: a study of law and policy arising from a ‘State of exception’

The use of armed drones in undeclared warzones pose various challenges to well established rules of international law. The US drone policies rest on shaky legal grounds, are ambiguous in nature and have been justified by reinterpretation of international law. The UK government’s use of drone strike in Syria shows a new problematic trend. The frequency of armed drones by few states outside area of active hostilities has normalised the use of force and generated a permanent state of exception. Mainstream research on targeted killings has focused on legality of US strikes in Pakistan but largely ignored the problematic role of Pakistan, in particular, the military violence of the Pakistani military in the tribal areas. The case study of Pakistan highlights that the drone strikes are directed against a population that is marginalised within the targeted state. The study argues that the special status of Federally Administered Tribal Areas (FATA) has allowed the US to conduct drone strikes without any accountability. The US has been targeting groups with varying degree of closeness to Al-Qaeda in multiple territories based in Yemen, Pakistan, Somalia and Syria. The study established with the help of control test devised by the International Court of Justice in Nicaragua case that the associations between Al-Qaeda and these groups or organisations is very loose. Targeting groups who pose no threat to the US is both illegal and counterproductive. Therefore the extraterritorial targeting of terrorists who pose no threat to the US is a flawed strategy and must be reviewed

Effective Proactive and Reactive Defense Strategies against Malicious Attacks in a Virtualized Honeynet

Virtualization plays an important role in the recent trend of cloud computing. It allows the administrator to manage and allocate hardware resources flexibly. However, it also causes some security issues. This is a critical problem for service providers, who simultaneously strive to defend against malicious attackers while providing legitimate users with high quality service. In this paper, the attack-defense scenario is formulated as a mathematical model where the defender applies both proactive and reactive defense mechanisms against attackers with different attack strategies. In order to simulate real-world conditions, the attackers are assumed to have incomplete information and imperfect knowledge of the target network. This raises the difficulty of solving the model greatly, by turning the problem nondeterministic. After examining the experiment results, effective proactive and reactive defense strategies are proposed. This paper finds that a proactive defense strategy is suitable for dealing with aggressive attackers under “winner takes all” circumstances, while a reactive defense strategy works better in defending against less aggressive attackers under “fight to win or die” circumstances

Terrorism Against Democracy

This monograph approaches the problem of terrorism from the perspective of the process of a terrorist attack; that is, how terrorism is intended to “operate.” Comprehension of the intended process of the terrorist attack can help defeat terrorists, reduce terrorism, and avoid the damage that can result from poor responses to attacks. Part I of the monograph analyzes terrorism. Chapter 1 analyzes what terrorism is, and what kinds of acts are and are not terrorism. Chapter 2 analyzes the ways that terrorism is intended to operate on third-parties—the governments, organizations, individuals, and groups from which terrorists seek to elicit responses. Chapter 3 analyzes the causes of terrorism, and the threats that terrorism poses. Part II addresses what to do about terrorism—how to prevent terrorism, respond effectively to attacks, and defeat terrorists. Analysis of the steps of the terrorist attack shows that terrorism can be prevented and countered at each step. The monograph then addresses a general counterterrorism strategy. The monograph uses the Turner-Yamamoto Terrorism Model as a guide to comprehending terrorism and how to combat it. The model illustrates the steps of the terrorist attack, and shows how terrorism is intended to operate. Adapted forms of the model show different aspects of terrorism such as the role of the media in terrorist attacks, and why people choose to use terrorism. The model can be used to identify ways to prevent terrorist attacks, respond effectively if they occur, and reduce the use of terrorism. The model has other uses, such as to identify the characteristics of terrorism. These characteristics can show the differences between terrorism and other forms of political violence, and can be used to analyze incidents to determine whether or not they are acts of terrorism. The model helps identify which characteristics must be included in any definition of terrorism, evaluate the strengths and weaknesses of different definitions, and develop accurate and useful definitions. Appendices address the definition of terrorism, the problems involved with trying to obtain agreement on a definition of terrorism, and analysis of arguments that have been made to try to justify terrorist attacks. Analysis shows that terrorism can be accurately defined in more than one way, that obstacles to obtaining a widely agreed-upon definition can be overcome, and that none of the arguments that terrorists and their supporters use to try to justify terrorism are valid. The impetus to prepare this monograph came from Admiral Stansfield Turner’s course, “Terrorism & Democracy,” which he taught from 2002–2006 in response to the 9/11 attacks on September 11, 2001. During the period that he taught the course, he encouraged the development of a number of the principles in the monograph and included them in his course, and until his retirement was involved with many aspects of the monograph